Long-Term Efficacy and Safety of Linagliptin in Patients With Type 2 Diabetes and Severe Renal Impairment: A 1-year, randomized, double-blind, placebo-controlled study

OBJECTIVE: This placebo-controlled study assessed long-term efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with type 2 diabetes and severe renal impairment (RI). RESEARCH DESIGN AND METHODS: In this 1-year, double-blind study, 133 patients with type 2 diabetes (HbA(1c) 7.0–10.0%) and severe RI (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m(2)) at screening were randomized to linagliptin 5 mg (n = 68) or placebo (n = 65) once daily, added to existing background therapy. The primary efficacy end point was HbA(1c) change from baseline to week 12. Efficacy and safety end points were assessed after 1 year. RESULTS: At week 12, adjusted mean HbA(1c) decreased by −0.76% with linagliptin and −0.15% with placebo (treatment difference, −0.60%; 95% CI −0.89 to −0.31; P < 0.0001). HbA(1c) improvements were sustained with linagliptin (−0.71%) over placebo (0.01%) at 1 year (treatment difference −0.72%, −1.03 to −0.41; P < 0.0001). Mean insulin doses decreased by −6.2 units with linagliptin and −0.3 units with placebo. Overall adverse event incidence was similar over 1 year (94.1 vs. 92.3%). Incidence of severe hypoglycemia with linagliptin and placebo was comparably low (three patients per group). Linagliptin and placebo had little effect on renal function (median change in eGFR, −0.8 vs. −2.2 mL/min/1.73 m(2)), and no drug-related renal failure occurred. CONCLUSIONS: In patients with type 2 diabetes and severe RI, linagliptin provided clinically meaningful improvements in glycemic control with very low risk of severe hypoglycemia, stable body weight, and no cases of drug-related renal failure. The potential for linagliptin to spare insulin and provide long-term renal safety warrants further investigations.